I need to finish some project that involves independently controling 6 dc motors salvaged from old mobile phones.The question is what kind of circuit do I need.Do I really need protection from collapsing m field having in mind that motors are really small?
P.S. I apologize for my bad English I am from Serbia.
Diode costs 15 cents. Arduino costs...?
Why not include one??
See...
Do motors need to reverse? Or are they running only one direction?
If only one direction then you can use simple motor drive circut:
There is no need to drive them in both directions.Tx.
In the above circuit you also need to connect the motor supply battery negative terminal to the arduino reference or ground point to provide a return path for the transistor base current.
The issue is not the motor size, its the inductance of the windings, best to include the diode. I suspect the motors are rated for 3V or so rather than 5, but they will probably survive running a bit faster than normal.
For those who might be confused... when someone above said...
connect the motor supply battery negative terminal to the arduino reference or ground point
he/ she wasn't giving you a choice of places to connect, he was just naming it two ways. In particular, you would not make the connection for this to "Vref" akak "AnalogRef"